Try-hard is an adjective used to describe an individual who:
1) will try very hard to be good at something or fit in and eventually fails.
2) in videogames (such as Call of Duty or Halo) tries so hard to be good they end up losing sight of just having fun. This individual can become aggressive with other players if they are in a losing situation. In this sense the term can be used to describe players who are being relatively successful.

It must be noted that it is not uncommon for individuals to falsely accuse others of being a try-hard in order to make themselves feel better for their own inability to fit in or poor performance. If confronted by such an individual evaluate the accuser as well as yourself and remember there is a difference between trying and trying too hard.

1) Look at Nick, he is such a try-hard interjecting in a conversation he knows nothing about to try to look cool.

1) Look at that player "0Ace", he is such a try-hard camping with an AK74u rapid fire and all pro perks but he still has a 0.50 KDR.

2) That player "CampHeavyAce" might have a 3.0 KDR but he only uses OP weapons and camps. I wonder if he is actually having fun being such a try-hard...

A person who puts a large amount of effort into achieving a certain image, or counter-image, to the point where it is obviously contrived. Rather than achieving an image through genuine personality, the try-hard consciously attempts to fit a certain style through deliberate imitation, forced style, or scripted behavior. That is to say, he/she is trying hard to create an image.

Examples: An affluent, suburban dweller who makes great efforts to cover himself in tattoos and piercings; try-hard.

A person who wears certain items of clothing for the express intention of appearing "non-conformist", and flaunts it; try-hard.

Someone who purchases a motorcycle only to appear as a "bad-boy"; try-hard.

A person who shuns certain genres or styles of music or art simply because it does not fit his self-image, or the image he wants to portray; try-hard.

1. A face-saving insult used by someone who is feeling inadequate. Basically accuses anyone who is better than them at anything of putting in effort. Doubles as an excuse for sucking by implying lack of effort on the speaker's part.

2. An insult blatantly misused by 13-year-old kiddies in online gaming who, ironically, try very hard to win themselves and take it too seriously when they lose.

3. Someone who tries too hard to fit in. Easy to spot online because of their constant use of trendy internet slang such as "fail", "cool story bro", and "tryhard".

4. An Urban Dictionary writer that submits overly-long definitions for pointless phrases trying to get recogniton.

1. Guy mopping the bathroom at Subway: "All those people from my high school that got into Princeton and MIT, they're just a bunch of fucking tryhards."

3. That one douchebag that always brags about his 2500 Facebook friends: "o hai guys dat 1 nig hes a fuckin tryhard im all like yea i get blazed all the time and shit and i fuck bitches and got all these friends, then hes like dude i dont fucking care stop sending requests to me i dont know you, and i was all like o rly, cool story bro. yeah i fuckin pwned that fail loser tryhard. lol, shit man, im so cool. srsly, pay attention to me plz! guys? anyone?!"

A Tryhard is someone who trys too hard to be included in a group of people.
Someone that will copy anything someone else does / something other people in a group do, listen to, act like, or look like, To become accepted in the group.

Alec is such a tryhard, all of the bands he listens to, he gets off us, he can't get his own life.

In online video games, it is that guy who is giving it 110% all the time because winning and/or having a high kill/death ratio is more important than just having fun. Try hards are most common in games like Halo or Call of Duty and are frequently seen yelling at their teammates for dying a lot.

Gamer: lol I accidentally killed myself XD

Try Hard: SERIOUSLY?!?! STOP BEING AN IDIOT AND ACTUALLY TRY!!! WE HAVE TO WIN THIS! I'M GOING 16-4 RIGHT NOW!

when playing a game too seriously in which out burst of rage, offensive language and putting people down may occur in which losing the whole concept of having fun in a video game.

fact: when calling someone a "try hard", you yourself is considered a try hard.

xSniperGuy: wow you try hard, keep spraying me cuz thats all you can do
yuh_Madd Br0: why you mad... bro? its just a game. plus you should have stayed behind cover then popping out your head like a dumb @ss

PR0 xClutch: hey Meat hog, quit trying so hard pulling out your pistol and shit; fucken try hard.
M3At H0Gx215: calm your nuts, i ram out of ammo. what you want me to do, just stand there and let you kill me?